Viessmann Vitodens 222-F B2TA Installation And Service Instructions Manual page 170

Designs
External connection diagram
A7 Connection adaptor
A8 LON communication module
(accessories)
A9 Internal extension H1 or H2
(accessories)
S1 ON/OFF switch
S2 Reset button
X... Electrical interfaces
! Outside temperature sensor
? Flow temperature sensor, low
loss header
% Cylinder temperature sensor
(plug on the cable harness)
170
(cont.)
sÖ
Internal circulation pump
sK Cylinder primary pump
dG Gas solenoid valve
fÖ Power supply
lH Power supply for accessories
and Vitotrol 100
a-Ö
Fan motor
a-ÖA Fan motor control
aYA Gas pressure switch
aVG KM BUS